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WPAN-UWB Transmission Loss Measurements Around/Near A Soldier’s Protective Vest* M. Cross, P.E. MegaWave Corporation 6/20/11. Transmission loss includes antenna gains Other propagation considerations: Around-body/vest probably “creeping wave” Stationary? Dispersive?
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WPAN-UWB Transmission Loss Measurements Around/Near A Soldier’s Protective Vest* M. Cross, P.E.MegaWave Corporation6/20/11 • Transmission loss includes antenna gains • Other propagation considerations: • Around-body/vest probably “creeping wave” • Stationary? • Dispersive? • Multipath delay spread? • Doppler spread (probably of no consequence) * Sponsored by U. S. Army Natick Soldier RD&E Center
Validity of Narrowband Transmission Loss Measurements • Are narrowband measurements valid for UWB bandwidths? • Answer on page 585 of Pahlavan and Levesque* • Pr UWB = Pr NB [1/1-(W/2Fc)²] , where: • Pr = Received power • W = bandwidth • Fc = Center frequency • 1.5 dB error for W = 7.5 GHz, Fc= 6.85 GHz • Narrowband measurements reasonable * Pahlavan, K. and Levesque, A., “Wireless Information Networks,” Wiley, 2005
Transmission Loss: Conclusions • ≈ 83 dB maximum measured loss • Less loss with vest vs. nude agar-gel-filled phantom • Little difference: standing-prone-sitting in HMMWV • 100% connectivity with COTS UWB dongles between all end-points (some under armor) • Narrow-band ≈ UWB except for delay spread, etc. • Continuing measurement campaign: • Confirm MegaWave measurements • Opportunity to measure channel statistics • Will provide accurate and detailed information for system design